Grand Paris Express Delays Deepen

First sections of Lines 16 and 17 are now due in 2028, prolonging the wait for better connections across Paris’s northern and eastern suburbs

The Grand Paris Express has revised the opening schedule for Lines 16 and 17, postponing their first passenger services until autumn 2028 and further extensions until autumn 2029. The delay reflects the complexity of commissioning a shared automated control system, but it also postpones promised improvements in access to employment, education and public services for communities outside central Paris.

The Société des grands projets, the public body overseeing the network, confirmed the new timetable after its supervisory board met on 24 September. The first section of Line 16 will run from Saint-Denis Pleyel to Parc du Blanc-Mesnil, while Line 17 will initially connect Saint-Denis Pleyel with Le Bourget Airport.

Both sections are now scheduled to open in autumn 2028. Line 16 is expected to reach Noisy-Champs a year later, while Line 17 should be extended to the Parc des Expositions at Villepinte at the same time.

The final section of Line 17, from the exhibition centre to Le Mesnil-Amelot, remains scheduled for completion by the end of 2030.

A shared automation problem

The revised dates are closely linked to the postponement of Line 15 South, which is now expected to enter service in autumn 2027. Lines 15, 16 and 17 use the same automated train-control architecture, limiting how quickly the system can be commissioned across several routes.

In its official timetable announcement, the project authority said its technical review had established that nine to twelve months would be needed between the opening of Line 15 South and the first services on Lines 16 and 17.

The authority has also changed the geographical scope of the opening phases. It said this would allow technical teams to concentrate on the common section of Lines 16 and 17, the Aulnay operations centre and the junction where the two routes separate.

The commissioning challenge extends beyond completed tunnels and stations. Automated railways require signalling, train-control software, platform equipment, rolling stock and operational procedures to function as one safety-critical system. Testing must demonstrate not only that trains can run, but that the network can respond safely to equipment failures, emergencies and disruptions.

A new working group will bring together the Société des grands projets, the system supplier, regional transport authority Île-de-France Mobilités, RATP Infrastructures and the ORA operating consortium. The supervisory board has also heard from independent experts and the head of Siemens Mobility France, whose consortium is responsible for deploying the transport system on Lines 15, 16 and 17.

Outer suburbs carry the consequences

The delays are more than a construction-management problem. Line 16 was designed to create faster links between communities in Seine-Saint-Denis and the eastern suburbs without requiring passengers to travel through central Paris. Its route includes areas where residents have long faced indirect journeys to major employment and education centres.

Line 17 has a different but related purpose. It will connect Saint-Denis with Le Bourget, the Villepinte exhibition district and, eventually, the area around Charles de Gaulle Airport. The route is intended to improve access both for travellers and for workers in one of the region’s largest employment zones.

An Insee study of Grand Paris Express station districts found that the network’s 68 station neighbourhoods already contained almost 934,000 salaried jobs at the end of 2022. It also identified substantial differences between employment-rich districts and predominantly residential areas, illustrating why faster orbital transport matters for social and economic mobility.

For residents, another year of delay can mean continued reliance on crowded buses, multiple transfers or private cars. It also affects local authorities, employers and housing projects whose planning has been aligned with anticipated opening dates.

The delay therefore creates a transparency obligation. Communities need regular, comprehensible information about technical progress, remaining risks and whether revised dates remain achievable. A timetable becomes especially consequential when households and businesses make long-term decisions around it.

Line 18 remains on course

The latest announcement was not entirely negative. The first section of Line 18, linking Massy-Palaiseau with Christ de Saclay, remains scheduled to open in December 2026. Four stations have received positive assessments from safety commissions, and final transport-system validation began in September.

Line 18 uses a different control system and is therefore not directly affected by the sequencing problem facing Lines 15, 16 and 17. Its initial section is expected to serve around 70,000 students, researchers, teachers and employees on the Saclay plateau. An extension to Orly Airport is planned for autumn 2027, followed by completion of the route between Versailles Chantiers and the airport in 2030.

The contrasting progress underlines the central difficulty of the Grand Paris Express: it is not a single railway opening, but a collection of interdependent systems being introduced across one of Europe’s largest metropolitan regions.

Its long-term case remains strong. Rail investment can reduce dependence on cars, widen access to opportunity and support lower-emission travel, priorities also reflected in wider European efforts to make transport less carbon-intensive.

But the public value of the project will ultimately be measured in dependable services, not construction milestones. The revised schedule gives engineers more time to establish a safe and stable network. It also extends the wait for the suburban communities whose daily mobility the Grand Paris Express was created to transform.